Pin centering and paralleling instrument



Feb. 23, 1954 w MANN 2,669,780

PIN CENTERING AND PARALLELING INSTRUMENT Filed Feb. 5, 1953 2Sheets-Sheet l Arvin W. Mann IN VEN TOR.

Feb. 23, 1954 A. W. MANN PIN CENTERING AND PARALLELING INSTRUMENT FiledFeb. 5, 1953 2 Sheets-Sheet 2 Fig. .9

6 80 lllllll g Fig. 6

g. 7 I QIIIEWQ a0 Arvin W. Mann INVEN'TOR.

BY WWW E Attorney:

Patented Feb. 23, 1954 PIN CENTERING AND PARALLELING INSTRUMENT Arvin W.Mann, Fort Lauderdale, Fla. Application February 5, 1953, Serial No.335,285

9 Claims.

This invention relates to restorative dentistry and more particularly toa device especially adapted for use in obtaining a hard cast or modelfrom an elastic impression in which the individual prepared teeth in thecast can be removed for convenience in using the reseated in their exactoriginal position in the base of the cast again resulting in a solidcast. This, then is truly a "master cast.

Elastic impression materials such as hydrocolloid, enable the detist toobtain a more accurate reproduction of the oral structures. The materialis inserted into the mouth in a fluid state, held in an impression tray.it is then allowed to gel, or induced to gell by introducing cold waterthrough a water jacket in the impression tray, and after completegelation, is removed from the mouth. Its elastic nature allows theimpression material to spring out of undercuts after gelation with anegligible distortion. A hard model or cast is obtained by pouringhydrocal into such an impression, allowing it to set hard and thenseparating it from the impression. This model or cast is then the mostaccurate reproduction of the mouth structures that is possible. Anyprosthetic appliance restoring individual teeth or combinations of teethif made to fit the model accurately, should then fit the mouthstructures with the same accuracy.

It is therefore the primary object of this invention to provide meansfor simplifying the pouring of the hydrocal into the elastic impressionmaterial to obtain a hard model or cast so as to provide dowel pinscentered in each prepared tooth, and parallel to each other which willallow said prepared teeth to be removed and then reseated accurately intheir original positions in the master cast.

The construction of this invention features the use of a clamp which hasa plurality of tapered apertures therein for reception of the dowelpins. These dowel pins are adapted to be centered in the impression of atooth a small distance above the elastic impression material. Then thepins may be removed from the vicinity of the impression, the impressiontray removed from its indexed position in the instrument, hydrocalpoured into it, and both pins and impression returned to their exactoriginal positions. The dowel p ns can then be positioned exactly asthey were when previously centered due to the action of this device.

Still further objects and features of the invention reside in theprovision of a pin centering and paralleling of the nature describedthat is strong and durable, simple in construction and manufacture,capable of being readily produced for wide distribution in the dentalfields at a relatively low cost, While being highly effective inachieving highly accurate reproductions while using the new techniquesnecessary for proper handling of elastic impression material.

These, together with the various ancillary objects and features of theinvention which will become apparent as the following descriptionproceeds, are attained by this pin centering and paralleling instrument,preferred embodiments of which have been illustrated in the accompanyingdrawings, by way of example only, wherein:

Figure 1 is a perspective view of the entire instrument;

Figure 2 is a vertical sectional view as taken along the plane of line22 in Figure 1;

Figure 3 is an enlarged sectional detail view of the clamp member andthe bracket pivotally attached to the clamp member;

Figure l is a perspective View illustratingone of the clamps used forcentering and paralleling the dowel pins comprising important elementsof this invention; 7

Figure 5 is a sectional detail view illustrating in particular thetapered apertures in the clamp member and the tapered dowel pin;

Figure 6 is a bottom plan view of one of the clamp members;

Figure 7 is a top plan view of a clamp member showing the device asprovided with a set screw having a slotted head;

Figure 8 is a view of the modified form of the invention similar to thatof Figure '7 but showing the set screw being provided with an Allenhead; and

Figure 9 is a top plan View of a further modification of the inventionemploying a Phillips head screw.

With continuing reference to the accompanying drawings wherein likereference numerals designate similar parts throughout the various views,reference numeral Hi generally designates a base to which a fitting I2is secured by screws, bolts or fasteners It. The fitting I2 is providedwith a tubular flange it havin a set screw it threadedly secured thereinfor locking engagement so as to support and hold a vertically extendingstand 26. There is also secured to the base It a cylindrical member 22having a recess 24 therein for reception of the socket elements 2t and28 forming one portion of the ball and socket joint including thespherical member 3!! which is attached to an upwardly extending standard32.

A threaded rod 34 is provided for tightening the socket elements 26 and28 into clamping engagement with the spherical ball 3d. The upper end ofthe standard 32 terminates in an annular flange 36 to which a tray 38preferably formed from a transparent synthetic plastic material issecured by means of bolts 40. Obviously, the tray 38 may be formed fromany other material as may be desired but the use ofthe: aforesaidmaterial has its advantages in enabling-the operator to more easilyremove the plaster index holding the impression tray after using.

'Slidably embracing the stand. 2-0 is; anclamp A knurled headed thumbscrew; 4.4

member 42. is used to lockingly adjust the clamp member 52 at anydesired height and position on the stand 20. The clamp member 42isprovidedwith bi-- furcations 46 and 4! between which there is receiveda bracket 48 which is mounted for pivotal screw. 5.3;p1usia washeris'.adaptedt -lockingh;

h ld the Supportv plate.- 56; in an adjusted position relativetoy-theymounting plate St. The support.pIateEfi-isproVidedzwithianarcuate configuration asat. fifldmorderthatthedowel pin clamps as,

indicated-.at;$2.may berarranged insuch matnher as to permit the dowelpin 54 to havingthein anchors. 66, arrangedto, conform. with: thecontours of a jawsand; center oftthe-prep-ared teeth of. ourimpression.

Referring nowpar.tioularly to Figures "r through 9 wherein thedoweltpin'clamps6-2;and the dowel. pin: 6% forming; the mostimportant elements. ofa the invention I are: illustrated. it will be seen. that each,- of;the; doweL. pin. clamps I 5-22 are formed with a fixed lower jawlit-.zandrmovable upper; jaw. 10.. Theupper jaw it: is,- pro- Vided-Witha; recess. '22 within which inner: rib T4 is embraced.' Theinner.Ylbiformed on the, connectionIla-interconnecting'thelower jaw 10 with afixed portion 78 used inzsupporting the upper movable jaw it.Attachedto' the-upper jaw. 10-115 a guide rod-1 all-which. extendsthrough; an aperture in the upper portionlts. Another aperture, 82informed inzthe-upperrportiontlii for. reception.- of, a; headed:internally threaded willhedrawn upwardly toward the .fixed. portion.

it?" or urgeddownwardly toward theloiverjaw 63..v A slot 95) for.reception. of a screw driver, isprovided in the. headed sleeve 8 1" andalter.- natively as is, shown inF'igures 8 and" tan. Allen head 9| maybe provided for reception of" an Allen wrench or a Phillips headed "mayalternatively be used; An outer reinforcing rib: 92""is;

provided for, the clamp trend 1 extends about thev fixed portion 78';the. connecting portion. it. and. the lower jaw, BB2 Theportionoflthe.rib.

92.011, the lower. jaw. lifiperforms the ..additional function ofproviding the lower surface of the jaw 88 with portions of varyingdepth. This is advantageous since a plurality of tapered apertures 94are drilled into the lower jaw 68 for reception of beveled dowel pins64. Hence, when the dowel pins 64 are positioned in the portion of therib 92 they will extend somewhat below the dowel pins placed in the jaw68 proper thus permitting: greater flexibility in the: use. of thisdevice. \Sometiines clampswith a smooth, fiat lower jaw 68 without rib92 are used to permit all pins to be evenly positioned in lower jaw 68.These. are. desirabl in addition to clamps with rib; 92"on lower jaw 68.It is to be noted that the anchors 66 are provided with ridges andrecessesih order that the plastic material being used in the cast may.become bonded thereto thus assuring against the pins being accidentallydisengaged.

In operation, after the impression has been taken. it. isplaced. inaplaster of: Paris matrix on tray, 58'. 'Ehen, theclampsfiz and thepins.are. attached to the support. plate 56.- withthe anchors 56 of. thepins: 613 positioned. a small distance. above the prepared teeth. oi anelastic impression. materiall impression. The support plate. 526 ispreferably formed: fromrai transparent plastic materialinorder that theimpressionniay. continuously be observed thus preventing any accidentaldistortion. orv destructionof the. impression. Then, theclamps,.dowel.-pins.84, and the. entire. bracket. t8; may, be. rotated:upwardly. astis shown in. the.dottedlinesdnffifigure 3: and this.impressioncan beremoyedlirom its plaster oi Paris-matrixon tray58,.filled1with .liydrocal mixture for. molding. the cast, and.returned; to originalpositibnbn tray, 58... Priorto the set.- ting oithe hydrocal mixture:the:bracket- 48;will be depressed. so. asto.immerse. the. anchors 65. in the hydrocal. mixture. This' mixture. maybe heaped up. about the. anchors :ifsuch is necessary. so as toinsure.aproper. bond. In.this manner each of the desired teeth.may, be.provided, with a centrally located dowellpirr. eventhough theimpressions. of the. teeth. arev not in view. after the hydrocal.mixturahas beeirpouredi.

Since. from .the foregoing, the construction and advantages of' thispin. centering and. parallels ing instrument are readily, apparent;furtherdescription is believed to be unnecessaryi.

However, since numerous modifications; willreadily occur; to those.skilled in. the. artiafter. a;- consideration' of 1 the foregoingspecification and accompanying drawings,. it is. not. intended. to limitthe. invention to.the. precise. embodiment-- shown and; described, butalL- suitable modificationsand. equivalents maybe readilyresorted to asdesired.

What is claimed-a :=new.-:is.- asviollowsz.

1...A.-. dowel. pin centering; and paralleling. instrumentfor:restorative dentistry; comprisi'ng'ia; clampv for engaging, assupport: said. clamp havin r an upper jaw andafilower clampingijawadapted to I hold said plate :therebetweem. a'iplui rality-oi;spacedupwardly extending;and-tapermg:

apertures in clamp. and; a. plurality oftaperedi dowel, pins. receivediin said: apertures; saidv dowel. pins: being. irictionally. heldby saidclamp, insaicl aperturea.

2-..... dowel... pin centering..- and paralleling.

-. rality; of. spacedupwardlyextending and tapering;-

apertures in said clamp, and a plurality of tapered dowel pins receivedin said apertures, said dowel pins being frictionally held by said clampin said apertures, the under surface of said lower jaw having more thanone portion each of varying depth, said apertures being arranged inparallel rows along the said portions.

3. A dowel pin centering and paralleling instrument for restorativedentistry comprising a clamp for engaging a support plate, said clamphaving an upper jaw and a lower clamping jaw adapted to hold said platetherebetween, a plurality of spaced upwardly extending and taperingapertures in said clamp, and a plurality of tapered dowel pins receivedin said apertures, said dowel pins being frictionally held by said clampin said apertures, said apertures being arranged in parallel rows.

4. A dowel pin centering and paralleling instrument for restorativedentistry comprising a clamp for engaging a support plate, said clamphaving an upper jaw and a lower clamping law adapted to hold said platetherebetween, a plurality of spaced upwardly extending and taperingapertures in said clamp, and a plurality of tapered dowel pins receivedin said apertures, said dowel pins being frictionally held by said clampin said apertures, said clamp being supported by said plate over a tray,said plate being adjustably secured to a bracket, a base, a stand onsaid base, a clamp member vertically adjustable on said stand, saidbracket being pivotally attached to said clamp member.

5. A dowel pin centering and paralleling instrument for restorativedentistry comprising a clamp for engaging a support plate, said clamphaving an upper jaw and a lower clamping jaw adapted to hold said platetherebetween, a plurality of spaced upwardly extending and taperingapertures in said clamp, and a plurality of tapered dowel pins receivedin said apertures, said dowel pins being frictionally held by said clampin said apertures, said clamp being supported by said plate over a tray,said plate being adjustably secured to a bracket, a base, a stand onsaid base, a clamp member vertically adjustable on said stand, saidbracket being pivotally attached to said clamp member, the under surfaceof said lower jaw having more than one portion each of varying depth,said apertures being arranged in parallel rows along the said portions.

6. A dowel pin centering and paralleling in strument for restorativedentistry comprising a clamp for engaging a support plate, said clamphaving an upper jaw and a lower clamping jaw adapted to hold said platetherebetween, a plurality of spaced upwardly extending and taperingapertures in said clamp, and a plurality of tapered dowel pins receivedin said apertures, said dowel pins being frictionally held by said clampin said apertures, said clamp being supported by said plate over a tray,said plate being adjustably secured to a bracket, a base, a stand onsaid base, a clamp member vertically adjustable on said stand, saidbracket being pivotally attached to said clamp member, said aperturesbeing arranged in parallel rows.

7. A dowel pin centering and paralleling instrument for restorativedentistry comprising a clamp for engaging a support plate, said clamphaving an upper jaw and a lower clamping jaw adapted to hold said platetherebetween, a plurality of spaced upwardly extending and taperingapertures in said clamp, and a plurality of tapered dowel pins receivedin said apertures, said dowel pins being frictionally held by said clampin said apertures, said clamp being supported by said plate over a tray,said plate being adjustably secured to a bracket, a base, a stand onsaid base, a clamp member vertically adjustable on said stand, saidbracket being pivotally attached to said clamp member, said clamp memberhaving a bifurcated outer free end portion, said bracket being pivotallysecured within said bifurcated free end portion, said bracket having aprojecting stop member extending inwardly of said bifurcated portion andselectively abutting against said clamp member to provide a limit stopto the rotation of said bracket relative to said clamp member.

8. A dowel pin centering and paralleling instrument for restorativedentistry comprising a clamp for engaging a support plate, said clamphaving an upper jaw ani a lower clamping jaw adapted to hold said platetherebetween, a plurality of spaced upwardly extending and taperingapertures in said clamp, and a plurality of tapered dowel pins receivedin said apertures, said dowel pins being frictionally held by said clampin said apertures, said clamp being supported by said plate over a tray,said plate being adjustably secured to a bracket, a base, a stand onsaid base, a clamp member vertically adjustable on said stand, saidbracket being pivotally attached to said clamp member, said clamp memberhaving a bifurcated outer free end portion, said bracket being pivotallysecured within said bifurcated free end portion, said bracket having aprojecting stop member extending inwardly of said bifurcated portion andselectively abutting against said clamp member to provide a limit stopto the rotation of said bracket relative to said clamp member, the undersurface of said lower jaw having more than one portion each of varyingdepth, said apertures being arranged in parallel rows along the saidportions.

9. A dowel pin centering and paralleling instrument for restorativedentistry comprising a clamp for engaging a support plate, said clamphaving an upper jaw and a lower clamping jaw adapted to hold said plattherebetween, a plurality of spaced upwardly extending and taperingapertures in said clamp, and a plurality of tapered dowel pins receivedin said apertures, said dowel pins being frictionally held by said clampin said apertures, said clamp being supported by said plate over a tray,said plate being adjustably secured to a bracket, a base, a stand onsaid base, a clamp member vertically adjustable on said stand, saidbracket being pivotally attached to said clamp member, said clamp memberhaving a bifurcated outer free end portion, said bracket being pivotallysecured within said bifurcated free end portion, said bracket having aprojecting stop member extending inwardly of said bifurcated portion andselectively abutting against said clamp member to provide a limit stopto the rotation of said bracket relative to said clamp member, saidapertures being arranged in parallel rows.

ARVIN W. MANN.

References Cited in the file of this patent UNITED STATES PATENTS Number

